Liquid filter cap



FIG. 1 is a perspective view of the liquid filter cap;

FIG. 2 is a front elevational view of a liquid filter cap;

FIG. 3 is a top plan view of a liquid filter cap;

FIG. 4 is a bottom plan view of a liquid filter cap; and,

FIG. 5 is a right side elevational view of a liquid filter cap, with the left side elevational view being identical thereto.

The broken line showing is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a liquid filter cap, as shown and described. 